An attractive manner of showing off a picture or a photograph involves placing an oval mat about the view of interest. Furthermore, the oval, when cut into the mat, should have a clean cut with a beveled edge. Moreover, the oval should have the particular overall size as well as the relative lengths of its longer and shorter axes to most propitiously set off the view inside. Oval cutters now in use do not achieve these objectives. One type of cutter employs a complicated system of bars and rods placed over a mat in order to cut the desired oval. However, this complicated mechanism may show signs of wear, become imprecise, and requires a significant economic outlay. Furthermore, the size of the mat that it may work on, of course, is limited by the overall dimensions of the superstructure supporting the cutter itself.
A variant of this type of cutter employs an overhead superstructure that actually utilizes a turntable for mounting the mat. Again, this type of structure limits the size of the mat that can undergo cutting, involves a substantial economic outlay, and may not always prove accurate after extended use.
U.S. Pat. No. 4,233,736 to R. W. Duggins et al. shows a cutter which employs a string or cable placed around two positioning pins on the surface of the mat. This type of system requires substantial manual dexterity to maintain the cable taut around the pins. It also demands substantial effort to properly position the pins and determine the length of the cable to obtain an oval with the overall desired size as well as the requisite differences between its larger and smaller axes.
A further type of cutter employs one of several different cams suspended over the mat to achieve the desired oval. This system suffers from the lack of complete adjustability of the ovals' dimensions. As with other superstructures, it also limits the size of the actual mat that it can operate upon.
Another cutter places two pins, separated from each other, on axes that cross each other perpendicularly. While avoiding many of the problems associated with the above cutters, it shows a serious lack of continuous adjustability of the ovals' various dimensions. As a consequence, the search for an inexpensive, adaptable, and fully adjustable oval cutter continues.
A further problem encountered with oval and circular mat cutters concerns the initial incision of the cutting knife into the mat itself. The knife of course displays some degree of flexibility. The mechanism holding the knife does not have total rigidity. As a result, where the knife first cuts through the mat, it displays a tendency to avoid the exact line of the desired oval by a small amount. This has often caused the users of such equipment to employ a file to remove the rough spot created by the inaccurate initial incision of the mat. As a consequence, the desire remains for a cutter that will not leave rough spots at the initial insertion of the knife into the mat.